3GPP Long Term Evolution, LTE, is the fourth-generation mobile communication technologies standard developed within the 3rd Generation Partnership Project, 3GPP, to improve the Universal Mobile Telecommunication System, UMTS, standard to cope with future requirements in terms of improved services such as higher data rates, improved efficiency, and lowered costs.
The Evolved Packet Core, EPC, is the core network of the LTE system and is an evolution of the packet-switched architecture used in GPRS/UMTS. The separated sub-domains of previous mobile generations of circuit-switching for voice and packet-switching for data is now realized in the EPC as packet switched architecture only. The main components of the EPC are the Serving Gateway, SGW, the Packet Data Network, PDN, Gateway, PGW, and the Mobility Management Entity, MME.
In many countries operators and Internet service providers are today obliged by legal requirements to provide stored traffic data generated from public telecommunications and Internet services for the purpose of detection, investigation and prosecution of crime and criminal offences, including terrorism.
Usually a public official, for instance a judge, is in charge of authorizing investigation on target persons, allowing to activate lawful interception, LI, on their communications or to query on data retention databases. The authorization paper is conventionally referred to as a “warrant”, which is provided to law enforcement agencies, LEA.
According to a received warrant, the law enforcement agency may set targets of interception and/or query data retention databases.
Existing payload handling methods in an EPC network are neither flexible nor performance oriented. When the payload increases with increased usage of the network, the processing board (for example the PGW) can be overloaded, but it is not flexible to scale. That is because of the limited capacity of the processing board; incoming and outgoing packets make use of I/O resources, computing resources and memory resources so that with increased payload, the processing board resources will eventually be overloaded. This is a limitation of the current EPC network node. Especially when LI is requested, performance gets even worse because of the increasing payload over the network, when the packets to be intercepted are duplicated and the duplicates are sent to the LEA.